The invention concerns a programmable switching device for the controlling of the timing sequence of functions in devices. At the inputs of the programmable device are input signals which cause the carrying out the functions and which releases output signals which are associated with individual steps of the functions which are to be carried out at set times. A pulse generator, a combinational circuit provided with at least one programmable matrix, and a state register which is connected thereto carry out the functions.
In communication engineering and electronic data processing devices, switching devices are provided which control the time sequence of functions in the devices. These switching devices are customarily constructed of a plurality of binary switching elements and storage elements. These switching elements and storage elements are put together by the designer of a switching device of this sort. The kind and the number of the switching elements and storage elements, as well as their arrangement in the switching device in the case of given functions to be carried out, are set according to the discretion of the designer. The internal logic functions of the switching device are first completely defined in this processing step and are documented in the form of a logic plan. This process has the result that the structure of the switching device particularly in the case of irregular networks, is nonuniform and is often very complicated topographically. With this, the representation is vague and function changes can only be carried out with great difficulty. Further, the specification of the switching device must proceed at the level of the switching and storage elements, because the logic functions are completely defined only at this level.
From German AS No. 2,657,404 incorporated herein by reference, a switching device is known where the structure of the switching and storage elements is pre-defined, so that a functional sequence diagram can be unambiguously presented which represents a random function. This switching device contains a plurality of control units which are provided in each case with a storing input level and which produce control signals with the use of matrices. These control signals on the one hand represent the output signals and on the other hand together with the input signals are fed to the input stages. In the case of this known switching device, the control units are arranged either hierarchically or in parallel. Each control unit controls the carrying out of at least one function.
From the publication "Short Haul Transmission System of the Teletypewriter 1000", Siemens Magazine 50 (1976), supplement "Teletypewriter 1000", pages 30 through 33, a programmable switching device is known which contains a switching device which is formed from two programmable matrices, a main matrix and an output matrix, and to which device input signals are fed. The output matrix produces the output signals, while the main matrix is connected with a state register and a pulse generator. In the state register, operating states are stored at points in time which are determined by the pulse generator. The operating states are determined in dependence upon the input signals and preceding operating states in the main matrix, whereas the output matrix produces the output signals in dependence upon the input signals and the preceding operating states.
In the case of both known switching devices, the input signals are fed directly to the switching device or respectively, to the matrices, so that, for each input signal, one column is provided in the corresponding matrix. The known switching devices therefore require relatively involved matrices, in the case of which the redundancy contained in the input signals is not taken into consideration.